


The Thing Hiding Under The Bed

by lieano



Category: Haikyuu!!
Genre: Alternate Universe - College/University, Alternate Universe - Creatures & Monsters, Halloween, M/M, Slow Burn
Language: English
Status: In-Progress
Published: 2018-10-10
Updated: 2018-10-10
Packaged: 2019-07-29 01:58:44
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,219
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16254356
Author URL: https://archiveofourown.org/users/lieano/pseuds/lieano
Summary: An unexpected shiver down your spine. A shadow moving in the corner of your eye. The things that go bump in the night. That was who Yuu was. He was a monster. For 10 years he had lived under Asahi's bed, scaring him every night. And he wasn't going to stop now just because Asahi was going to college.





	The Thing Hiding Under The Bed

**Author's Note:**

> HAPPY HALLOWEEN!! HAPPY BIRTHDAY NOYA!!! HAPPY SPOOPY SEASON EVERYONE!!! I've been wanting to write this fic for a while now and I finally did it. For someone who goes around talking about how Asanoya is my OTP to end all OTP's I hardly ever write for them, it's terrible. Oh, also, I'm super bad at tagging so I'll probably update the tags as we go if I realize I forgot anything. And there will probably be other character in the fic later, I will add them as we go. Anyway I'm going to be working on a ship week for the next 7 days but I wanted to get the first chapter of this up for Noya's birthday so the second chapter will come out in maybe a week and a half? Ish? It won't be too long, I promise. And I'm gonna try to have the whole fic done and uploaded by the end of the month. For now, enjoy this little prologue-y-ish chapter. :)

As soon as he was able, Yuu went out in search of his own home. He was young and he ran entirely on instinct. When he was a little wiser he would be able to plan his nests, but his first one would be impulsive. He struck gold when an overwhelming stench of fear found him. Yuu’s eyes dilated and drool ran down his jaw. He had never tasted anything like it, and he wasn’t even close to the source. He broke out in a run. It was the most electrifying sensation he had ever felt. He was magnetised to it. He wanted more.

The trail of fear brought him to a child’s bedroom. There was no one inside but it was barely noon so the human who typically occupied it was probably out doing whatever it was humans did in the daylight. After his mad dash, Yuu registered that he was a little sleepy. Stubbornly, he didn’t want to rest right away. He wanted to do a little investigating while his new roommate was gone. 

The room belonged to an ‘Asahi’ according to a plaque on the door. He played a competitive game for which he had earned a couple of small trophies. Yuu only knew a little bit about human sports and he didn’t recognize this one with its big net. Asahi seemed to have fun playing it, though, according to the pictures on his dresser. 

A silent yawn ripped through Yuu. Asahi looked like a comfortable boy. He would have to rest well if he wanted Asahi to be less comfortable. 

As an afterthought, Yuu stole and destroyed the only night light in the room. Then he crawled under the bed, his body flattening out to accommodate the small space. And then exhausted and excited all at once, Yuu bled into the shadows. He became one with the darkness. And he waited. 

*** 

An unexpected shiver down your spine. A shadow moving in the corner of your eye. The things that go bump in the night. That was who Yuu was. He was a monster. A type of creature known only to humans through fairy tales and horror stories. Adults cautioned their children about monsters, but didn’t believe in them. It baffled Yuu, but he had to admit it made his job easier. 

Monsters were as diverse as humans. They came in all shapes and sizes. Yuu’s specific abilities were dependant on the dark. He had black hair, black eyes, a black cloak. He was built to blend in, to create paranoia in peripheral vision. And just in case the shadows did nothing, he was also sharp. Pointy hair, pointy teeth, long pointy nails. A fear of the dark was subjective but a fear of being pierced or scratched or otherwise bodily harmed was pretty universal. 

Not that Yuu would ever actually hurt a human. Monsters fed off fear. It was their sustenance. Yuu only had to scare people, he never actually had to spill blood. The only danger to him was the possibility of his prey growing immune to his spooks through exposure. Monsters were solitary, roaming creatures for that reason. So even though he was young and still had much to learn, Yuu had left his mother. He was on his own. 

His mother was probably thankful he was gone. Not that she didn’t love him, but Yuu had been told time and time again that his excitable nature made him a liability to the shadows that he called home. He liked to be loud and fast when he was made for being sneaky and slow. When he was very young, he had stolen a lightning bolt out of a storm and put it in his hair. Because it was cool. He was _determined_ , now that he was independent, to prove that he could be a successful monster even with his aesthetic still in tact. 

Yuu was about to prove all the haters wrong because his first human, this child called Asahi, reeked of fear. Yuu bristled with anticipation for nightfall. He wanted to meet Asahi, his very own scaredy cat. 

Finally, after resting all day, Yuu heard a soft spoken string of good night wishes outside the bedroom door. Yuu blinked as he peered from the crack under the bed. His yellow cat-like pupils were highlighted by their black scleras. His lightning bolt flickered in and out of existence. Yet, Yuu went unnoticed when the room flooded with light and Asahi entered. 

He was a plain looking child. Stocky, brunette hair, timid eyes. He noticed right away that the night light was missing and the resulting surge of fear made Yuu prickle. He vibrated with anticipation, but he managed to tamper it down. The biggest mistake a young monster could make was to throw away patience and pounce too quickly. Yuu wouldn’t make a rookie mistake like that. He would wait like he was taught to. Between the hours of 3 am and 4 am he would be his strongest. It was the time of night when human fear and monster magic eclipsed. Even sleeping humans were scared of the witching hour. 

Yuu wasn’t starving, though. Now that Asahi was here, he was feasting. He hadn't even made his presence known and already the fear was sweet and plentiful. They were both in for a very exciting night. 

*** 

Scaring was an art and Yuu was a natural talent. Over the span of a few months, he slowly built up the tension. He would shake the mattress and cast unnatural shadows on the walls. Asahi was a silent screamer. He hid under his covers and shook, paralyzed with fear. He would ask his parents to check under his bed before he went to sleep, but they never found Yuu. He was one with the shadows. And to his complete delight, his lightning bolt never gave him away. _‘Take that, Mother.’_

As time moved he learned what scared Asahi the most. A clawed hand gripping his sheets or a figure crawling across the floor only to vanish. His spooks were well timed, well crafted things. 

Yuu had been taught that after a while, one human would grow immune. He wasn’t finding that to be the case with Asahi. The boy was always scared. Still, after a year Yuu wondered if he should move on. Find a new human to test out his tricks, see if they truly were as good as he suspected. His lightning bolt crackled with wanderlust, flashing bright lights across the dark room as Asahi slept. 

Before he committed to leaving, he had a special move he wanted to try. Thunder without a storm. He already had the lightning, the second part should come naturally to him. Asahi might actually wet the bed. It would be the cherry on top of the sundae that was their time together. 

Three am struck and Yuu’s face appeared under the bed. It was time. His finale. His terrifying parting gift to the human who had given him so much. His opened his mouth to twice the natural human size and braced himself. 

Just before the sound could be released, movement in the corner of the room caught Yuu’s attention. Slowly, painfully, with a long creek, the closet door opened. 

Yuu halted his thunder The door wasn’t him. Asahi was still sleeping peacefully. The only explanation was that a new monster was encroaching on his territory. _‘Oh hell no.’_

Yuu understood, of course. Asahi’s fear could be smelled for miles. And yeah, he was leaving soon. But it didn’t matter. He hadn’t left _yet_. Asahi was his. This other monster would have to go, he decided. 

The mattress above Yuu shifted as the ominously creaking door came to a pause. Asahi was going to wake up and see claws gripping the door. Yuu closed his jaw part way and pursed his lips. He could make Thunder more powerful if it was aimed properly. Probably. He didn’t actually know how Thunder was going to work yet, but now was the time to find out. 

With a dance of lightning across the room, the boom burst from Yuu’s lungs. It shot like a tornado to the closet from under the bed. The sound was at a frequency only human children and beasts could hear, but trapped in an improvised whirlwind of Yuu’s breath even Asahi was deaf to. The other monster wasn’t. They took the full force of the trick, like a firework going off in someone’s face. Wordlessly, they broke from the closet and fled out the bedroom window. And Asahi sept through the whole thing. 

Yuu sank back into the shadows, exhausted. His powers were not meant to be used against other monsters, let alone as weapons. But it had been worth it. He would have to try Thunder the way he intended it later. 

*** 

Yuu never got to try his new trick on the human boy. The next night another monster appeared. And the night after that, same story. Before Yuu knew it, years had passed. He lived off of second hand fear when the Asahi accidentally awoke during the skirmishes. And he never left. He stayed for ten years, protecting Asahi from unknown monsters. He didn’t notice, until the day Asahi started packing his things. 

He had grown from a young boy into a young man. He had sprouted from a weed and was now incredibly tall and incredibly muscular. It was from all the jumping he did during his sport, which he had stuck to faithfully. Yuu had watched tapes from under the bed whenever Asahi needed to study his form. He was really good. Probably. He had more hair too, some sweeping across his shoulders and some dotting his chin. He almost looked tough now. But he still had those soft eyes and a nervous slouch. Yuu knew, probably better than anyone, that Asahi was still just as timid and frightened as he always had been. 

And now he was… leaving? 

“Do you have everything?” Asahi’s mother asked, gripping his elbow as they both glanced around the now nearly empty room. 

“If I don’t I can come back for some things.” Asahi looked wistful. A little puff of fear escaped him, but it tasted different from the fear Yuu was used to. 

_‘He’s coming back?’_ Yuu wondered. He wanted to know how long it would be. One time Asahi had gone on a trip for two weeks and he almost starved. He had been younger and weaker back then, but still. 

Asahi’s mother glanced up at him with a cocked eyebrow. “I don’t want to see you until winter, you hear? You need to stay on campus in the beginning and make friends!” 

_‘Winter?!’_ Yuu’s eyes widened. 

Asahi just chuckled. His voice was a deep baritone now that rivaled even Yuu’s Thunder. “Of course. Then I guess you can mail me anything I missed. Though I really think I have everything.” 

_‘No! You forgot me!’_

Asahi sucked in a rattling breath and his mother patted his cheek. “You okay, darling?” 

“Just nervous.” That much was very clear to the anxiously snacking Yuu. 

“College will be the most memorable journey of your life. I know you will be amazing.” 

They embraced and then it was over. The room fell to darkness. Yuu bristled with… anger. He was angry! Asahi was leaving him! After all the time Yuu had invested in him, he was gone, just like that! It wasn’t fair. 

“Well, Yuu,” he said to himself as he gripped at the darkness under Asahi’s bed that had been his home for a decade. “You always thought about leaving. Seeing the world. Now is a good excuse to do so.” 

He waited for nightfall. It was so tricky traveling during the day when the shadows were few and far between. But as soon as a consuming darkness fell on the city, Yuu was ready. He phazed out of the bed and stretched. Then he took one last glance around the room and crawled out the window. 

It was a cool night. Yuu bristled with delight at feeling the wind through his cloak again. Asahi’s scent was easy to pick up, too. It was the same nervous fear he’d had before he left. Yuu savored the smell and chased it. He would follow it to the ends of the Earth if he needed to. Because the taste of Asahi was unlike any other. Yuu loved it. 

His journey was nothing if not exciting. He didn’t pass many frightened people in the dazzling neon lights of the city. But he still had a thrill dashing from shadow to shadow, quick and light and small. It was fun. 

Yuu paused in the street to re-orientate himself. In his excitement he had almost lost Asahi’s trail. But the sweet scent enveloped him again sure enough. He tried to meld into the shadows in the pavement a moment too late. Bright lights flooded Yuu and a loud horn blared. A large vehicle was hurtling toward him. Yuu smirked. No problem. 

He faced the ground below his feet and unhinged his jaw. The horror of the truck driver fueled him as the force of Thunder launched him in the air. He grinned a sharp, toothy grin at the human as he soared out of harm's way, flipping and twisting over the truck. 

When he stuck the landing and molded back into the shadows before the stunned driver could pull over to investigate, Yuu muttered to himself, “Rolling Thunder. Get it?” And then he laughed at his own joke as he picked up the trail again, because no one was around to appreciate it. 

The rest of the trip was without conflict. Yuu traced Asahi almost to dawn, finding him finally in a huge multistory building. Every room inside was a bedroom and the whole place was shrouded in fear. Not the kind of fear most monsters liked, though. Childhood fear that they could manipulate with their powers was preferred. But Yuu was easy going and he didn’t hate this. 

Yuu identified Asahi’s room easily. It was small. Way smaller than his other bedroom. He had a bed and a desk and a pop-up closet and that was about it. Of course, he wasn’t home. Yuu, very tired from the stunts of the night, quickly melted under the bed and let Asahi’s familiar scent embrace him like a blanket. He was still home. 

*** 

Yuu was roused from his sleep by soft sobs rattling the bed. For once the shaking was not him. He peaked around the edge of the mattress and his heart started pounding. Asahi was crying. Why? 

The soft patter of a rainstorm muted his sobs a little. Yuu second guessed his plan to scare Asahi. He was clearly already upset about something. Then again, maybe some classic spooks from his childhood would take his mind off whatever was- 

The wind of the storm suddenly blew open the window. Rain sprayed throughout the room. Yuu’s lightning bolt flickered, trying to help him regain awareness of his surroundings. That was how he saw it. A monster perched on the window sill. His wispy, translucent skin blended in with the billowing curtains. His toothy grin was the only light in the night sky behind him. He had come for Asahi. Yuu growled. It didn’t matter where they were. Asahi was still _his_. 

Yuu shot out from under the bed in a flash of lightning. He crouched between the monster and the rest of the room and snarled. 

“Oh,” said the monster. “I haven’t seen you around here before. Are you new?” 

“Yes,” Yuu said. His voice cracked. It had been so long since he had said anything out loud with his normal diction. “Just got here this morning.” 

“Welcome,” the monster said cordially. “Unfortunately I have to ask you to find a different room. I have been haunting this dorm for a century. I have first crack at all new students.” 

Yuu shook his head. “Not this one. Asahi is my human. And I _will_ fight for him.” 

He pursed his lips for a directed Thunder. The monster was made of clouds so it was not a challenge. The monster clutched the window sill desperately but Yuu advanced until the apparition was gone in the rain, yelling profanities at Yuu as he went. Yuu latched the window shut and then turned. He intended to return to his home under the bed, but he froze. 

Asahi was looking right at him. 

Ten years was a long time, but Yuu was very good at his job. _Never_ had Asahi seen him in his true form. The fact of that hit Yuu all at once. He knew Asahi inside and out but… Asahi barely knew he existed. Until now. Now he knew. 

Yuu raised a clawed hand and waved. No point in hiding anymore. “Hey, Asahi.” 

Asahi, speechless, looked between Yuu and the window, his mouth opening and closing. Finally he swallowed and squeaked, “Wh-who? What?” 

Yuu rubbed the back of his neck embarrassed. “Uh, I’m Yuu. I’m, uh… I’m the monster that lives under your bed.” 

Another beat of silence, then Asahi whispered, “You’re real?” His voice was almost as shaky as the rest of him. 

“Yes. I’ve been with you for 10 years. It’s nice to formally meet-” 

“I have been going to a _therapist_ for 10 years!” Asahi hissed. His fear and a hint of anger spiked. The anger left a bad taste on Yuu’s tongue. “My night terrors ever since I was 8… The thing that’s been hiding under my bed for a decade… It was all real… It was all _you_?” 

“Yes,” Yuu admitted, flinching. “Well, some of them. I had to chase off a lot of other monsters too. I’m sorry. Did I hurt you? I always thought a little harmless scaring was no big deal for humans.” 

Asahi looked at the storm outside his window again and hesitated. “You fought off that other… Have you done that a lot?” 

Yuu fidgetted. This fateful meeting was not going the way he had always envisioned it. “Yes. You’re afraid of everything, Asahi. Monsters are attracted to your scent.” 

Whatever it was Yuu said, it seemed to click into place with something in Asahi’s brain. A light flickered across his expression and he put his head in both of his hands. “So, are you a monster or my guardian deity?” 

This made Yuu perk up. He was a little boastful as he said, “Well, I’m clearly no deity. But I like the guardian thing.” 

To his utter shock, Asahi cluckled. His hooded eyes met Yuu. The lightning bolt in Yuu’s hair sparked with his restrained emotions. 

“Um, Yuu? If I go to sleep now, will you… wake me up later to scare me? Because I had a kind of long day and I’d like to sleep…” 

Yuu grinned and when Asahi flinched at the sight of his teeth he put them away and shook his head. “Not tonight. I’ll watch over you. Peacefully.” 

“Okay…” Asahi sighed heavily. “This is… Weird… Maybe it’s a nightmare.” 

Yuu winked and phased back into the shadows. From every corner of the room his voice echoed, “I guess you’ll find out tomorrow night. Sleep well, Asahi.”


End file.
